The present invention relates to golf balls, and more particularly to golf balls having one or more deep dimples that extend through the outer cover layer to and/or into one or more layers or components thereunder.
A number of one-piece, two-piece (a solid resilient center or core with a molded cover), and multi-layer (liquid or solid center and multiple mantle and/or cover layers) golf balls have been produced. Different types of materials and/or processing parameters have been utilized to formulate the cores, mantles, covers, etc. of these balls which dramatically alter the balls"" overall characteristics.
For certain applications it is desirable to produce a golf ball having a very thin cover layer. However, due to material and/or equipment limitations, it is often very difficult to mold a thin cover. Accordingly, it would be beneficial to provide a technique for producing a relatively thin outer cover layer.
Moreover, retractable pins have been utilized to hold, or center, the core or core and mantle and/or cover layer(s) in place while molding an outer cover layer (or potentially other layers) thereon. These pins are retracted during the latter stages of the molding process with the still somewhat fluid cover or mantle material filling the void left by the pins.
The retractable pins, however, sometimes produce centering difficulties and cosmetic problems (i.e. pin flash, pin marks, etc.) in the lands or dimples during retraction, which in turn require additional handling to produce a golf ball suitable for use and sale. Additionally, the lower the viscosity of the mantle and/or cover materials, the greater the tendency for the retractable pins to stick due to material accumulation, making it necessary to shut down and clean the molds routinely. Furthermore, the pins also produce a xe2x80x9ccold weldxe2x80x9d when their voids are filled during molding. This is deleterious to durability as the cover may fail by cracking through the filled pin voids after many hits.
Accordingly, it would also be desirable to provide a method for forming a thin outer cover layer or intermediate layer on a golf ball without the use of retractable pins.
One aspect of the invention is to provide a golf ball having a dimpled cover that is thinner than traditional cover layers. The ball also produces a favorable combination of spin, resiliency and durability characteristics.
Another aspect of the invention is to provide a golf ball having one or more dimples in a relatively thin outer cover layer that extend to, and/or into at least the next inner layer or core of the ball. The cover layer has an outer surface and defines a plurality of dimples along the outer surface of the cover layer. At least one of the dimples is defined by the cover layer such that the dimple extends through the cover layer. The ball may optionally comprise a thin barrier coating between the cover and the core that limits the transition of moisture to the core.
The present invention also provides, in a further aspect, a golf ball comprising a core, a mantle layer disposed on the core, and a cover layer disposed on the mantle layer. The cover layer has an outer surface and defines a plurality of dimples along the outer surface of the cover layer. At least one of the dimples is defined by the cover layer, the mantle layer, and the core such that the dimple extends through the cover layer to and/or into the mantle layer or core.
In another aspect, the present invention provides a golf ball comprising a core and a cover layer disposed about the core. The cover layer defines a plurality of dimples. At least a portion of the plurality of dimples extends through the cover layer to and/or into the core. The dimple depth is from about 0.002 inches to about 0.140 inches. The ball is preferably produced without the use of retractable pins.
An additional aspect of the present invention is to provide to a golf ball with a thin cover and one or more deep dimples which extend through the cover layer. The ball has a favorable combination of playability properties yet which may be manufactured more cost effectively and without the use of retractable pins and/or problems associated with prior balls.
The invention accordingly comprises several compositions, components and steps and the relation of one or more of such compositions, components and steps with respect to each other. Moreover, the invention is directed to articles possessing the features, properties, and the relation of elements exemplified in the following detailed disclosure.